This is one of the shuttlecraft from the Starship Enterprise. The Galileo Seven was lost in the Maursaki 312 Nebula with Spock, McKoy, Scotty and other assorted crewmen. It landed on a planet inhabited by giant ape like creatures that killed off some of the crew. Scotti had to drain the phasers to use as fuel to get off the planet. However, the phasers were the only line of defense against the giants. A great episode.